The prime minister responded: "Calm down dear, calm down, calm down. Listen to the doctor. Calm down and listen to the doctor."

The phrase "calm down dear" was made famous by pleasure-loving film director and critic Michael Winner.

Mr Cameron attempted to continue reading the quote but eventually gave up, instead adding: "I said calm down. Yes, calm down dear - I'll say it to you if you like... I'm not going to apologise, you do need to calm down."

A party spokesperson said: "This isn't a laughing matter." Backbencher Chuka Umunna tweeted: "The mask slips: at PMQs just now Cameron says "Calm down dear" to either Angela Eagle or Yvette Cooper. Totally unbecoming of a PM."

Kevin Brennan added: "Cameron's mask slips again this time to reveal his patronising view of women."

She added: "Women in Britain in the 21st century do not expect to be told to 'calm down dear' by their prime minister."

The ensuing row in the Commons chamber brought exchanges between Mr Cameron and Miliband to a premature end.

Speaker John Bercow twice intervened, rebuking MPs and telling them their behaviour left "a very bad impression on the public as a whole and the other people".

Earlier exchanges in PMQs had focused on the economy and NHS reforms. Mr Miliband had claimed the economy had "flatlined in the last six months", after GDP figures released this morning suggested economic stagnation over the last three quarters.

Mr Cameron attacked Mr Miliband for "talking the economy down" and accused him of hoping for the economy to shrink.

"We've got debts, tragically because of what we've inherited, but we've got interest rates like Germany," he pointed out.

The Labour leader responded by criticising the content of the prime minister's answers.

"What world is he living in? What extraordinary complacency, what terrible complacency from this prime minister!" he responded.

The second set of questions, which culminated in the "calm down dear" remarks, focused on the coalition government's plans on the NHS.

"When you make changes in public services it is a challenge to take people with you," Mr Cameron said.

But he was riled by Mr Miliband's criticisms over waiting times and the no-confidence vote in health secretary Andrew Lansley passed by the Royal College of Nursing earlier this month.

An earlier version of this article repeated allegations against Payam Tamiz originally made in the Evening Standard. The Standard has now accepted that those allegations were false and defamatory. Politics.co.uk has removed them.